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Aging‐dependent proteolysis of NF‐κB in human fibroblasts
Author(s) -
Ikebe Tetsuro,
Jimi Eijiro,
Beppu Mahiro,
Takeuchi Hiroshi,
Nakayama Hideki,
Shirasuna Kanemitsu
Publication year - 2000
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/(sici)1097-4652(200002)182:2<247::aid-jcp14>3.0.co;2-s
Subject(s) - p50 , leupeptin , hela , proteolysis , microbiology and biotechnology , fibroblast , biology , chemistry , protease , biochemistry , transcription factor , cell , enzyme , in vitro , gene
We investigated the NF‐κB–like factor induced in the late‐passage human oral mucosal fibroblasts stimulated with interleukin‐1 (IL‐1). Compared with the NF‐κBs of HeLa cells and early‐passage fibroblasts, the NF‐κB–like factor of late‐passage (passage 15) fibroblasts migrated faster in the electrophoretic mobility shift assay (EMSA) and behaved like a 70–80 kDa protein in the gel filtration chromatography. Both antibodies against p50 and p65 subunits of NF‐κB could supershift the small NF‐κB–like factor of late‐passage cells in the EMSAs. A 47‐kDa band was detected in late‐passage fibroblasts by immunoblotting against p50. The mobility of the trypsin‐degraded NF‐κB of HeLa cells corresponded to that of the small NF‐κB–like factor of late‐passage fibroblasts in the EMSAs. Furthermore, when the nuclear extracts of the IL‐1–stimulated HeLa cells were incubated with those of the IL‐1–stimulated old fibroblasts, the p65‐p50 NF‐κB band disappeared, leaving behind a small NF‐κB–like band. This reduction of NF‐κB was prevented by the addition of a cysteine protease inhibitor leupeptin. These results suggest that the small NF‐κB–like factor of late‐passage fibroblasts is a part of the NF‐κB truncated by aging‐induced protease(s). J. Cell. Physiol. 182:247–255, 2000. © 2000 Wiley‐Liss, Inc.